C++ Handlw DragDrop

So I am continuing to learn/play with C++ with TBX and now I have got a simple WIMP app built I was looking into some more advanced features like handling drag and drop and loading writing files. I trying to write a simple test app that will handle a file (just a text file for now) being dropped onto the applications main window and then read the file and do something on the back of that. But I haven’t found any documentation on how to do this with C++? I have searched the PRMS and a few go-to places like Steve Fryatt’s great guides but nothing is jumping out at me. I’m assuming the information is in fact staring me in the face but there’s a good chance I am just missing it due to me still not knowing what to really look for.

I’d love someone to write a book on building C++ apps on RISC OS aimed at people who already know how to code in perhaps a modern object oriented language on Windows/Linux/Mac.

I’ve never done it in TBX, but tbx::OpenerManager.add_opener() might be what you’re after.

Looking again probably an opener is for when someone double-clicks a file in the Filer; for drag-and-drop onto the app you’ll be wanting tbx::LoaderManager.add_loader() I guess.

Use the Window add_loader method to process a file dropped onto a window. The reference guide installed with TBX has the details. Iconbar has a similar method for a file dropped onto the icon bar.
There is also a User guide shipped with TBX. Unfortunately I’m not getting time to really look at the state of the documentation, but please feel free to email me with corrections or areas that need clarification. My email is in the doc.

Thank you both for the reply. Ok trying out Window add_loader is next on my list of things to try with c++ plus TBX. Yes I have been using the user guide a lot and it’s really good so thumbs up for putting it together. Hopefully as I gain a little experience with C++ I will be able to better understand the reference guide a little more.

I have been able to get the add_loader to work from looking at the reference guide and produced the following test app. The second test app I was trying to create an instance of the loader class and pass this to the window.add_loader() method but when I run this and drop a file on the window I get a segmentation error. From googling this is likely to do with how I have created the instance of the loader class but I am not sure how else it can be done.

   #include "tbx/application.h"
#include "tbx/autocreatelistener.h"
#include "DragDrop2wnd.h"

using namespace std;

int main()
{
   tbx::Application my_app("<DragDrop2$Dir>");

   DragDrop2Wnd window_handler;

   my_app.set_autocreate_listener("Window", &window_handler);

   my_app.run();

   return 0;
}

#include "DragDrop2Wnd.h"
#include "tbx/window.h"
#include "tbx/displayfield.h"

using namespace tbx;

/**
 * Set up listeners and commands for the window.
 */
void DragDrop2Wnd::auto_created(std::string template_name, Object object)
{
  Window window(object);
  DisplayField fileNameDisplay(window.gadget(0));
  DDLoader _loader;
  _loader.setDisplayField(fileNameDisplay);
  window.add_loader(&_loader);
  //_loader.setWindow(window);

}

   #include "DDLoader.h"

bool DDLoader::load_file(tbx::LoadEvent &event){
 if(event.from_filer()){
       _fileNameDisplay.text(event.file_name());
  }
       return false;
}

void DDLoader::setDisplayField(tbx::DisplayField fileNameDisplay){
  _fileNameDisplay = fileNameDisplay;
  _fileNameDisplay.text("Ready for file");
}

/*void DDLoader::setWindow(tbx::Window window){
  _window = window;
  _window.add_loader(this);
}*/

    #include "tbx/loader.h"
#include "tbx/displayfield.h"
#include "tbx/path.h"
#include "tbx/window.h"
class DDLoader : public tbx::Loader{
  public:
  tbx::Window _window;
  tbx::DisplayField _fileNameDisplay;
  void setDisplayField(tbx::DisplayField fileNameDisplay);
  void setWindow(tbx::Window window);
  virtual bool load_file(tbx::LoadEvent &event);
};

   #ifndef _DragDrop2WND_H_
#define _DragDrop2WND_H_

#include "tbx/autocreatelistener.h"
#include "tbx/loader.h"
#include "DDLoader.h"

/**
 * Class to set up listeners an variables when the single
 * window is shown.
 */
class DragDrop2Wnd : public tbx::AutoCreateListener
{
  public:
  //DDLoader _loader;
  virtual void auto_created(std::string template_name, tbx::Object object);
};

#endif